MILWAUKEE — As the Celtics took a Game 3 beating Friday night, the player they normally rely on to lift their physicality watched from the sidelines with a splint over his injured right thumb. Marcus Smart said he has felt “antsy” to return from a torn right UCL, which required surgery and has kept him out of the lineup since March 11.

After what Smart revealed Sunday morning before Game 4 of his team’s first-round series with the Milwaukee Bucks, the injury might not hold him out much longer. The guard said he plans to visit New York City to meet with a doctor Tuesday. If all goes well, Smart could potentially be cleared to return in time for Thursday night’s Game 6 (which will be played if the Bucks extend the series they currently trail 2-1).

“Right now that’s the plan,” Smart said.

Smart had previously suggested he hoped to return by Game 7 of the first round or the beginning of the second round, so the time...